Purpose
This subcommand is
a performance statistics operation that returns log cache counters,
such as the number of requests, hits, and waits on the log buffer
cache.
Format
syscall_parmlist
opcode 247 STATOP_LOG_CACHE
parms[0] offset to STAT_API
parms[1] offset to output buffer
parms[2] offset to system name (optional)
parms[3] 0
parms[4] 0
parms[5] 0
parms[6] 0
STAT_API
sa_eye char[4] "STAP"
sa_len int length of buffer that follows STAT_API
sa_ver int 1
sa_flags char[1] 0x00
SA_RESET 0x80 Reset statistics
sa_fill char[3] 0
sa_reserve int[4] 0
posix_time_high unsigned long high order 32 bits since epoch
posix_time_low unsigned long low order 32 bits since epoch
posix_useconds unsigned long microseconds
pad1 int
API_LOG_STATS
al_eye char[4] "ALOG"
al_size short size of output
al_version char version
al_reserved1 char reserved byte
al_reserved2 int reserved
al_buffersize int size of each buffer in K bytes
al_lookups_reserved int reserved
al_lookups int lookups/creates of item in log buffer cache
al_hits_reserved int reserved
al_hits int hits - number of items time item found in cache
al_writtenPages_reserved int reserved
al_writtenPages int number of log buffer pages written to disk
al_fullWaits_reserved int reserved
al_fullWaits int number of times new log buffer requires wait on prior
log pages
al nbsWaits_reserved int reserved
al nbsWaits int number of times new log buffer requires wait on new block
user I/O
al_reserved3 int[10] reserved
systemname char[9]
Return_value 0 if request is successful, -1 if it is not successful
Return_code
EINTR zFS is shutting down
EINVAL Invalid parameter list
EMVSERR Internal error occurred
E2BIG Information too big for buffer supplied
Reason_code
0xEFnnxxxx See z/OS Distributed File Service Messages and Codes
Usage notes
- Reserved fields and undefined flags must be set to binary zeros.
Related services
- Statistics Vnode Cache Information
- Statistics Metadata Cache Information
Examples
#pragma linkage(BPX1PCT, OS)
extern void BPX1PCT(char *, int, int, char *, int *, int *, int *);
/* #include <stdlib.h> */
#include <stdio.h>
#define ZFSCALL_STATS 0x40000007
#define STATOP_LOG_CACHE 247 /* Performance API queries */
#define u_long unsigned long
#define CONVERT_RATIO_TO_INTS(RATIO, INTEGER, DECIMAL) \
{ \
INTEGER = (int)RATIO; \
DECIMAL = (int)((RATIO - (double)INTEGER) * (double)1000.0); \
}
typedef struct syscall_parmlist_t
{
int opcode; /* Operation code to perform */
int parms[7]; /* Specific to type of operation, */
/* provides access to the parms */
/* parms[4]-parms[6] are currently unused*/
} syscall_parmlist;
typedef struct hyper {
unsigned long high; /* unsigned long reserved */
unsigned long low;
} hyper;
typedef struct API_LOG_STATS_t {
char al_eye[4]; /* Eye catcher = ALOG */
#define LS_EYE "ALOG"
short al_size; /* Size of output structure */
char al_version; /* Version of stats */
#define LS_VER_INITIAL 1 /* First version of log stats */
char al_reserved1; /* Reserved byte, 0 in version 1 */
hyper al_buffers; /* Number of buffers used */
int al_reserved2; /* Reserved for future use, 0 in version 1 */
int al_buffsize; /* Size in kilobytes of one buffer */
hyper al_lookups; /* Lookups/creates of item in log buffer cache */
hyper al_hits; /* Hits, number of times item found in cache */
hyper al_writtenPages; /* Number of log buffer pages written to disk */
hyper al_fullWaits; /* Number of time new log buffer requires wait on prior log pages */
hyper al_nbsWaits; /* Number of time new log buffer requires wait on new block user IO */
int al_reserved3[10]; /* Reserved for future use */
} API_LOG_STATS;
/* reset timestamp */
typedef struct reset_time {
u_long posix_time_high; /* high order 32 bits since epoc */
u_long posix_time_low; /* low order 32 bits since epoch */
u_long posix_usecs; /* microseconds */
int pad1;
} RESET_TIME;
/*********************************************************************/
/* The following structure is the api query control block */
/* It is used for all api query commands */
/*********************************************************************/
typedef struct stat_api_t
{
#define SA_EYE "STAP"
char sa_eye[4]; /* 4 byte identifier must be */
int sa_len; /* length of the buffer to put data into*/
/* this buffer area follows this struct*/
int sa_ver; /* the version number currently always 1*/
#define SA_VER_INITIAL 0x01
char sa_flags; /* flags field must be x00 or x80, x80 means reset statistics*/
#define SA_RESET 0x80
char sa_fill[3]; /* spare bytes */
int sa_reserve[4]; /* Reserved */
struct reset_time reset_time_info;
} STAT_API;
struct parmstruct
{
syscall_parmlist myparms;
STAT_API myapi;
API_LOG_STATS mystats;
char systemname[9];
} myparmstruct;
int main(int argc, char **argv)
{
int bpxrv;
int bpxrc;
int bpxrs;
int i;
double temp_ratio;
int whole,decimal;
STAT_API *stapptr = &(myparmstruct.myapi);
/* STAT_TRAN_CACHE *sttcptr = &(myparmstruct.mystats); */
char buf[33];
myparmstruct.myparms.opcode = STATOP_LOG_CACHE;
myparmstruct.myparms.parms[0] = sizeof(syscall_parmlist);
myparmstruct.myparms.parms[1] = sizeof(syscall_parmlist) + sizeof(STAT_API);
myparmstruct.myparms.parms[2] = 0;
/* Only specify a non-zero offset for the next field (parms[2]) if */
/* you are running z/OS 1.7 and above, and */
/* you want to query the log cache statistics of a different system than this one */
/* myparmstruct.myparms.parms[2] = sizeof(syscall_parmlist) + sizeof(STAT_API) + sizeof(API_LOG_STATS); */
myparmstruct.myparms.parms[3] = 0;
myparmstruct.myparms.parms[4] = 0;
myparmstruct.myparms.parms[5] = 0;
myparmstruct.myparms.parms[6] = 0;
memset(stapptr,0,sizeof(STAT_API));
memcpy(stapptr->sa_eye,SA_EYE,4);
stapptr->sa_ver=SA_VER_INITIAL;
stapptr->sa_len=(int) sizeof(API_LOG_STATS);
/* This next field should only be set if parms[2] is non-zero */
/* strcpy(myparmstruct.systemname,"DCEIMGVQ"); */
BPX1PCT("ZFS ",
ZFSCALL_STATS, /* Perf statistics operation */
sizeof(myparmstruct), /* Length of Argument */
(char *) &myparmstruct, /* Pointer to Argument */
&bpxrv, /* Pointer to Return_value */
&bpxrc, /* Pointer to Return_code */
&bpxrs); /* Pointer to Reason_code */
if( bpxrv < 0 )
{
printf("Error querying log cache, BPXRV = %d BPXRC = %d BPXRS = %x\n",bpxrv,bpxrc,bpxrs);
return bpxrc;
}
else
{
printf("%52s\n","Log File Caching Statistics");
printf(" \n");
printf("Buffers (K bytes) Requests Hits Ratio Written \n");
printf("---------- --------- ---------- ---------- ------ ----------\n");
temp_ratio = (myparmstruct.mystats.al_lookups.low == 0) ? 0.0 :
((double)myparmstruct.mystats.al_hits.low)/myparmstruct.mystats.al_lookups.low;
temp_ratio *= 100.0;
CONVERT_RATIO_TO_INTS(temp_ratio,whole, decimal);
decimal = decimal / 100; /* Just want tenths */
printf("%10u %9u %10u %10u %3u.%1.1u%% %10u\n",
myparmstruct.mystats.al_buffers.low,
myparmstruct.mystats.al_buffers.low * myparmstruct.mystats.al_buffsize,
myparmstruct.mystats.al_lookups.low, myparmstruct.mystats.al_hits.low,
whole, decimal, myparmstruct.mystats.al_writtenPages.low);
printf(" \n");
printf("New buffer: log full waits %10u NBS IO waits %10u\n",
myparmstruct.mystats.al_fullWaits.low, myparmstruct.mystats.al_nbsWaits.low);
printf(" \n");
if (0==ctime_r((time_t *) &stapptr->reset_time_info.posix_time_low, buf))
{
printf("Could not get timestamp.\n");
}
else
{ /* Insert the microseconds into the displayable time value */
strncpy(&(buf[27]),&(buf[20]),6);
sprintf(&(buf[20]),"%06d",stapptr->reset_time_info.posix_usecs);
buf[26]=' ';
buf[19]='.';
printf("Last Reset Time: %s",buf);
}
}
return 0;
}